Therefore, one could presume that such adapted tumour cells would also be more resistant to other insults that trigger the DNA damage‐induced ATM/ATR‐mediated responses, and therefore, such tumour population might already contain clones of cells a priori resistant, or more easily further adaptable, to the later clinical administration of genotoxic insults in the form of radiation or chemotherapy. This evidence concerns the gene ATM and neoplasm.